The short version
Final Round AI is the loudest brand in the AI interview copilot category — they claim ten million users, and they spend heavily on ads. But beneath the brand, the product has three structural weaknesses that account for 17% of their reviews on Trustpilot being one star: high latency, generic answers, and aggressive billing.
We built mirly as the explicit inversion. Below is a feature-by-feature comparison, with sources.
Latency
Final Round's published architecture batches transcription before calling the LLM. Their first-token latency in published reviews and community tests sits at 1,500–2,000 milliseconds. That is enough delay that interviewers consistently mention "I could tell they were reading an answer" in feedback.
Mirly runs on-device whisper.cpp on Apple Silicon for streaming partials in 60–80 ms, then fires a Groq Llama 3.3 draft on the first confident partial — speculative execution before the question is even finished. The first useful token lands in under 150 milliseconds.
| Metric | Mirly | Final Round AI |
|---|---|---|
| First-token p50 | <150 ms | ~1,800 ms |
| Streaming STT | On-device whisper.cpp | Cloud, batched |
| LLM warmup | Pre-connected WS | Cold per call |
| Cache hit rate | 85%+ within session | None disclosed |
Personalization
This is the single biggest gap. Final Round generates answers from a generic system prompt — every candidate, regardless of background, gets bullets like "audited existing IAM policies, implemented Access Analyzer, leveraged AWS Organizations…". We confirmed this by running the same question through Final Round's free tier and ours.
Mirly rebuilds the system prompt every session from your résumé, your target JD, and three to five STAR stories you paste once. The model is instructed to draw exclusively from your actual experience and is forbidden from contradicting your résumé. Same question, very different answer:
Final Round answer: "Audited existing IAM policies, implemented IAM Access Analyzer to monitor for unintended access, leveraged AWS Organizations for centralized user and group management..."
Mirly answer (Sam Patel profile loaded): "At Stripe the merchant team had 1,200+ IAM roles with overlapping policies. I built an analyzer in Go that diffed real CloudTrail traffic against role policies. Cut 87% of unused permissions in four months..."
The first reads like a CISSP textbook. The second is a story the candidate can actually tell.
Billing transparency
This is where Final Round's reviews collapse. Their auto-renewal pattern charges £249–£488 per year without notice, and customers report refund requests sitting in support backlogs for weeks. Their pricing page does not disclose the renewal terms; the Trustpilot pattern is consistent enough that "Final Round AI billing" auto-completes on Google.
Mirly does the opposite, on purpose:
- Monthly subscriptions are opt-in renewal — we email you five days before each cycle ends; if you don't click renew, nothing charges.
- Credits never expire and never auto-renew. Buy 1, 3, or 10 — use them whenever.
- No silent annual auto-renew. No surprise charges.
- Single-interview credit (£5) for users who only need it once — Final Round does not offer this.
Stealth
Final Round's overlay is reported visible on several screen-share configurations as of 2026 (Trustpilot reports). They use process disguise + window-level hiding, which is fragile against OS updates.
Mirly uses documented OS APIs — NSWindow.sharingType = .none on macOS, SetWindowDisplayAffinity(WDA_EXCLUDEFROMCAPTURE) on Windows. The same primitives Apple Pay uses to hide cards from screen recording, and 1Password uses to hide passwords. Tested 24 times a day on real OS instances; results published at our status page.
Pricing
| Tier | Mirly | Final Round AI |
|---|---|---|
| Free trial | 7-min trial, one per account | 1-min trial, then paywalled |
| Single interview | £5 (1-hour credit) | Not offered |
| Pack of 3 | £10 (£3.33 each) | Not offered |
| Pack of 10 | £20 (£2 each) | Not offered |
| Monthly | £29.99, opt-in renewal | £148 (Pro), silent auto-renew |
| Refund | Not offered — try the 7-min trial first | 7 days, support-ticket-gated |
Where Final Round wins
To be fair: Final Round has been live since 2023, has a polished marketing engine, and — for sheer brand recognition among first-time job seekers — they will outrank any new entrant for a while. If you want a category leader's customer-count signal and you are not sensitive to billing surprises or generic answers, Final Round is the safe choice.
If you want the answer to sound like you, and you do not want to wonder whether next month's renewal will hit your card without warning, switch to mirly.
The verdict
Mirly beats Final Round on the four dimensions that actually matter in a live interview: latency, voice match, billing honesty, and stealth reliability. Try the 7-minute free trial — your first call will tell you whether the difference is real.